A user terminal such as a smartphone may support wireless communication. The user terminal may include a subscriber identity module (SIM) for identifying a user in a network. In general, the SIM may be inserted into a terminal or may be separated from the terminal. If the SIM is separated from the terminal (i.e., if there is no SIM inserted into the terminal), the terminal may be in a “NO SIM” state. The terminal in the “NO SIM” state may provide only a limited service such as an emergency call.
Meanwhile, in addition to the SIM or alternatively, an embedded SIM (eSIM) which is soldered onto the terminal and is impossible to be inserted/separated into/from the terminal may be used. A terminal having the eSIM may download a profile of a mobile network operator (MNO) using over-the-air (OTA) to use a mobile communication service of the MNO and may enable the profile. The SIM/eSIM may be referred to as a universal integrated circuit card (UICC)/eUICC.
Since the eSIM is soldered onto a terminal contrary to a conventional SIM, the terminal into which the eSIM is loaded may fail to be in the “NO SIM” state in view of hardware. However, since the eSIM uses a manner of downloading a profile, installing the profile in the eSIM, and enabling the profile, only one profile may fail to be installed in the eSIM or installed all profiles may be disabled.
According to currently related standards, if there is an enabled profile in the eSIM, the eSIM should ensure to provide a default file system to a terminal (refer to a section 3.4.3 eUICC file structure of an SGP.22—RSP technical specification v.1.0 document). If receiving the default file system, the terminal may determine that there is a valid SIM. In this case, the terminal may perform an operation of transmitting a polling command to the eSIM on a periodic basis and verifying whether there is an available SIM (e.g., an international mobile subscriber identity (IMSI) value) and an operation of searching for an available network.
According to the related art, since the terminal having the eSIM performs an operation of transmitting a polling command or searching for a network although it is in the “NO SIM state” actually, unnecessary power consumption may occur. Further, in view of an MNO, unnecessary load may occur in a network due to a network search operation of the terminal.